The present invention relates generally to window frames that are mounted in wall openings, and to methods of installing window panes in such frames.
In commercial and industrial buildings, window panes arc generally secured in frames that are mounted in openings in the building structure. Such frames take many forms but typically include a sill, two side jambs and a header. A window pane receiving groove or the like is provided in the frame. A window pane is placed in the groove and sealant or a seal strip (generally referred to as glazing) is inserted into the groove on opposite sides of the window pane to seal and hold the window pane in place.
The inside dimensions of the window frame opening are smaller than the outer dimensions of the window pane, thus requiring some means for inserting the window pane into the window pane groove through the window frame opening. One way to accomplish this is to have removable window pane retainer strips that when removed, provide a larger frame opening permitting insertion of the window pane. Installation of the retainer strips around the periphery of the window pane secures it in the frame. The retainer strips are held in place by screws or some other fastener means. One such frame is disclosed in U.S. Pat. No. 3,323,262. This structure is very complex, requiring a large number of parts to work. The frame uses two-piece frame members that are clamped in place in the structural opening by screws cooperating with component parts of the frame members. Retainer strips abut the window pane when installed and are screwed in place around the entire periphery of the window pane to retain the window pane in place. U.S. Pat. No. 2,840,202 shows another window frame that is held in place in a structural opening by a tooth and pawl arrangement. The window pane is retained in place by a bead of glazing. While such designs have been somewhat effective in use, they are complicated in structure and require complex manufacturing and time consuming installation techniques.
Window frames and window panes used in commercial and industrial buildings can be large and many times need to be installed at elevated locations. This poses both safety and expense problems. When there is a pressure differential across the window pane, large forces can be generated making installation difficult. Also, the window pane needs to be positively secured in place to prevent loss of the window pane and any subsequent damage the loss may cause. Thus, window frames need to be effective in positively retaining the window pane and easy for installers to install in structures, both new and pre-existing. Many times, window installation is done at elevated positions making installer safety a major concern. Further, because elevated work is dangerous, it requires skilled workers who command high salaries. Thus, a window frame needs to be designed to provide for easy, sure, and quick installation, present minimal safety issues for the installer and reduce labor costs for installation. After the window frame is installed, the same concerns about safety and cost apply to the installation of the window pane in the window frame. In addition, the loss of a window pane during installation can cause a safety risk to people and property in the vicinity. Thus, the window frame needs to be adapted for easy, quick, and sure installation of the window pane.
After installation, window repair is frequently needed. Concerns over expense and safety are the same for repair as they are for initial installation. Thus, the window frame needs to be easy to operate to remove old panes and install new panes.
Thus, there is a need for a window frame that is easy and economical to manufacture and simple and quick to install in wall openings. The window frame should have a minimum number of parts that need to be installed to secure a window pane and provide for positive retention of the window pane.